Sorry, I can't help with your specific need, but perhaps can help point you toward the right direction.

While Gardenweb is a great place for some general chit chat about plants, your best bet for trades/donations is going to be the Facebook Passiflora Online group. There are nearly 1000 members, and several posts each DAY, not year...

Also, it would be remiss of me to not mention the Passiflora Society International as a great resource for meeting like minded people.